The present invention relates to exercise devices and in particular to cardiovascular conditioning exercise devices, such as jump ropes.
A wide variety of exercise programs are used to condition various different aspects of the human body. One type or "class" of exercise program involve weight training, weight lifting or other physical exercises that are directed to the development of the muscles or the strength of the participant. Typically, such programs involve physical exertion by the participant in order to work and fatigue certain muscle groups. Weight training and the like operate very effectively in order to produce such "strength" conditioning.
Although "strength" exercise programs, such as weight training, do result to some degree in an increase in blood circulation, such programs are minimally effective in conditioning the circulatory or respiratory systems. Normally, exercise programs directed to cardiovascular conditioning are structured quite differently from those designed for such "strength" conditioning. Cardiovascular exercise programs typically are made up of exercises that involve a high degree of movement, these exercises being performed quickly and repeated many times without interruption. The constant activity causes an increase in blood circulation and respiration. For example, aerobic dance, long distance running, cross country skiing and various other competitive sports involve such cardiovascular conditioning.
One problem associated with conventional exercise programs is that the exercises which are targeted towards "strength" building often do not produce adequate cardiovascular conditioning. The reverse situation also occurs with many exercises that are targeted toward cardiovascular conditioning. Further, the strength conditioning that is provided by most cardiovascular conditioning is usually limited to certain areas of the body. For instance, although long distance running is an excellent cardiovascular conditioning exercise, any resulting "strength" conditioning is limited to the runner's legs. Long distance running produces limited "strength" conditioning of the runner's upper body. For this reason, in order to obtain a complete workout, athletes normally combine a series of strength building exercises, such as weightlifting, with a series of cardiovascular conditioning exercises, such as running or jumping rope.
Another problem associated with most cardiovascular conditioning exercises is that the beneficial effects are only produced after lengthy, uninterrupted repetitions of the exercise. Some theories maintain that what cardiovascular conditioning occurs is produced predominantely toward the end of the workout, rather than being experienced as a proportionate effect equally distributed throughout the exercise repetitions. For this reason, cardiovascular conditioning is normally both very time consuming and monotonous.
One such exercise that is primarily targeted at cardiovascular conditioning is jumping rope. If a proper jump rope regime is followed, excellent cardiovascular effects are produced. Further, boxers and the like have long used jump rope exercises in order to develop "foot quickness" and balance. Although an excellent exercise for these conditioning purposes, jump rope exercise suffers from the problems noted above in that its beneficial effects are only recognized after relatively lengthy periods of exercise. Additionally, any "strength" developing effects produced by jump rope exercises are confined almost exclusively to the practitioner's legs.
Due to the popularity of jump rope exercises some prior artisans have attempted to improve its overall conditioning effect. Heretofore jump ropes have been fitted with discrete external weights in an attempt to provide a wider spacing between the cord lengths depending from the user's hands. Others have used jump ropes that have an increased weight. Although such weighted ropes are in some aspects an improvement over standard jump ropes, such weighted ropes exhibit certain deficiencies. Most weighted jump ropes provide a substantial hazard to the user and surrounding persons. If the rope inadvertently strikes the user or another person, injury is likely since the weighted section is moving at a high rate of speed. Additionally, the continuous sriking of the floor by the weights or weighted section has a tendency to damage or undesirably wear the floor surface and/or the rope.
Another problem experienced with previous weighted jump ropes is an undesirable tugging or jolting that is imparted to the user's arms by the rope as it circles the user. It is hypothesized that this jolting effect is produced due to the combined centrifugal and gravitational forces acted upon the jump rope. As the rope passes through its circle of travel it shifts from a downward to an upward direction of movement. It is hypothesized that it is this continual transition between movement assisted by gravity and movement resisted by gravity that produces the jolting effect. Another possible reason for this undesirable jolting effect is that in prior jump ropes weighted with discrete or fixed weights the load upon the rope is reduced to essentially zero when the weight strikes and is supported by the floor. As the load is reapplied by the weight a jolt results. This effect is magnified by slack or sagging of the rope while the weight is supported by the floor. Whatever the reason for this jolting effect, it results in an uncomfortable shock being imparted to the arms of the exerciser.